Antonyms for the phrase "said not a chance" include "said yes," "definitely," "for sure," "absolutely," "certainly," "without a doubt," "undeniably," "indisputably," and "positively." These antonyms convey a sense of confidence and certainty, in contrast to the dismissive and negative tone of "said not a chance." By using these antonyms, speakers can demonstrate their conviction and enthusiasm for a proposition, rather than simply rejecting it outright. This can make for more engaging and persuasive communication, and help build stronger relationships with others who share similar goals and values.